﻿ko.bindingHandlers.fadeVisible = {
    init: function (element, valueAccessor) {
        // Initially set the element to be instantly visible/hidden depending on the value
        var value = valueAccessor();
        $(element).toggle(ko.utils.unwrapObservable(value)); // Use "unwrapObservable" so we can handle values that may or may not be observable
    },
    update: function (element, valueAccessor) {
        // Whenever the value subsequently changes, slowly fade the element in or out
        var value = valueAccessor();
        ko.utils.unwrapObservable(value) ? $(element).show(100) : $(element).hide(100);
    }
};


ko.bindingHandlers.fadeClass = {
    init: function (element, valueAccessor) {
        // Initially set the element to be instantly visible/hidden depending on the value
        var value = valueAccessor();
        $(element).toggle(ko.utils.unwrapObservable(value)); // Use "unwrapObservable" so we can handle values that may or may not be observable
    },
    update: function (element, valueAccessor) {
        // Whenever the value subsequently changes, slowly fade the element in or out
        var value = valueAccessor();
        ko.utils.unwrapObservable(value) ? $(element).show(100) : $(element).hide(100);
    }
};


//custom binding to initialize a jQuery UI dialog
ko.bindingHandlers.jqDialog = {
    init: function (element, valueAccessor) {
        var options = ko.utils.unwrapObservable(valueAccessor()) || {};

        //handle disposal
        ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
            $(element).dialog("destroy");
        });

        $(element).dialog(options);
    }
};

//custom binding handler that opens/closes the dialog
ko.bindingHandlers.openDialog = {
    update: function(element, valueAccessor) {
        var value = ko.utils.unwrapObservable(valueAccessor());
        if (value) {
            $(element).dialog("open");
        } else {
            $(element).dialog("close");
        }
    }
};


ko.bindingHandlers.datepicker = {
    init: function (element, valueAccessor, allBindingsAccessor) {
        //initialize datepicker with some optional options
        var options = allBindingsAccessor().datepickerOptions || {};
        $(element).datepicker(options);

        //handle the field changing
        ko.utils.registerEventHandler(element, "change", function () {
            var observable = valueAccessor();
            observable($(element).datepicker("getDate"));
        });

        //handle disposal (if KO removes by the template binding)
        ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
            $(element).datepicker("destroy");
        });

    },
    update: function (element, valueAccessor) {
        var value = ko.utils.unwrapObservable(valueAccessor());

        //handle date data coming via json from Microsoft
        if (String(value).indexOf('/Date(') == 0) {
            value = new Date(parseInt(value.replace(/\/Date\((.*?)\)\//gi, "$1")));
        }

        var current = $(element).datepicker("getDate");

        if (value - current !== 0) {
            $(element).datepicker("setDate", value);
        }
    }
};